Patent Literature 1 discloses a fluid level detector that detects a level of a fluid stored in a tank. The fluid level detector of Patent Literature 1 has a body having a flat plate shape and a cover having a bottomed tubular shape. The body and the cover define a housing chamber. The housing chamber houses a float, a magnet, and a reed switch. The float and the magnet move up and down when the fluid level changes, and the reed switch detects whether the fluid level reaches a specified level.
According to Patent Literature 1, the body has a locking hole, and the cover has a hook extending toward the locking hole. The locking hole catches the hook, whereby the cover is fixed to the body.